The study by Drs Psaty and Kronmal and the accompanying Editorial by Drs DeAngelis and Fontanarosa regarding rofecoxib illustrate the recurring problem of discretionary or data-driven analysis. Given the possibility of selective analysis based on observed data and the risk of positive results due to chance alone, it is critical to know in detail which analyses were prespecified and when the prespecification occurred. This can only be done via a full protocol repository. With no protocol or a timeline documentation of its provenance, these details are never made public so that it is not possible to see how published analyses compare with protocol-specified analyses. This transparency is needed to be confident in the validity of the results.